There has been significant innovation in the field of passive decorative construction materials that act on ambient light in interesting ways. Chief among these are panel systems that have a range of materials embedded in transparent, translucent, or opaque sheets, e.g., sheet of glass used as room partitions. The companies involved in this field include 3form and Lightblocks. The types of materials that may be embedded in such sheets include both discrete pieces (e.g., wires, grass, leaves, flowers, pebbles, etc.) as well continuous films that add color and/or graphics. Further, these products may include a range of surface treatments, such as embossed patterns, grooves, specular finishes, matte finishes and anti-reflective coatings, among others. While some of these materials can create novel effects (like dichroic films whose apparent color shifts with view angle), there is no way to actively select or change the color characteristic or other visual appearance characteristic of the material after installation.